This invention involves a device to immobilize and stabilize the cervical vertebrae in an upright alignment, generally known as cervical traction orthosis of a patient.
Cervical traction orthotic devices have been used for some time to stabilize the cervical vertebrae, most often for patients with fractures of the cervical vertebrae. These devices generally include a semi-rigid vest constructed of polyethylene polymeric plastic formed sheet that is strapped around the patient's chest. Support rod members are structurally attached to the vest and extend upwardly to positions around the person's head. A rigid generally oval shaped ring is releasably attached to the upper ends of the support rods. The ring, generally in the form of an oval, has a raised section positioned to the rear of the patient's head with the balance of the ring being positioned generally horizontal. A multiplicity of horizontal holes are provided along the entire length of the horizontal portion of the ring. Surgical titanium threaded pins threadably engaged in the holes are adjusted and screwed through the ring to engage the skull and hold the patient's head in position.
The rings have been made of a variety of materials, stainless steel, titanium, aluminum, although the modulus of the latter material is generally too low, and, more recently, carbon fiber reinforced composite materials. An advantage of the composite material is that they do not affect the field when placed in the extremely strong magnetic field of the magnetic resonance imaging testing apparatus, generally referred to as "MRI". It is a common practice to place a patient having a fractured cervical vertebrae in an MRI apparatus. Sometimes these tests are prescribed for the fracture itself, but are also many times required because of other injuries or complications. The common stainless steel rings provide too much magnetic disturbance in the MRI scanner causing arcs, burns, and at the minimum, disruption of the testing procedures with false images. Unfortunately, problems arise with the carbon fiber reinforced composite materials including failure to maintain a stable thread and thus a firm positioning of the skull pins. The use of helicoil metal threads engaged directly into the horizontal holes of the carbon reinforced composite ring provide inconsistent results, variations in torque required to move the skull pins through the threads. If metal threads are not utilized and the threads are cut directly into the composite ring the threads are a high incidence particulate contamination source. There is a major concern of fine particulate being abraded off of the ring threads to the threads of the pin and ultimately possibly reaching the patient's skull. The very nature of the titanium skull pins are electrostatic in nature and positioned such that any particulate matter abraded or broken away from the carbon fiber reinforced rings tends to be attracted to the point of the skull pins, the very point in contact with the person' s skull. Such contamination can form an ulcer and possible entry into the patient's blood stream. Since the entry of foreign materials through the skin and to the skull creates a potential for great hazard to the patient, such risks cannot be tolerated.
An additional problem with present orthotic devices involves the necessity of reaching the patient's chest for emergency procedures. For example, if the patient were to suffer a cardiac arrest or even an arrhythmia, serious harm could come to the patient if either a substantial delay were to be required to remove the device or that the entire device had to be removed in order to reach the patient's chest. As a result, it has been desirable to have at least the front support rod members to be releasably hinged to allow access to the person's chest by allowing the vest to be peeled back in order to reach the patient's chest. Unfortunately, because of the angles involved from the chest to the head ring, the hinges tend to bind and become easily twisted and permanently damaged. Loosening the bolts and detaching the front support rods is too time consuming in case of a cardiac arrest.
Prior devices described in U.S. Pat. No. 4,620,530 to LANIER ET AL as well as all of the devices described in the patents and publications cited as references in that patent, all incorporated herein by reference, fail to satisfy the above needs nor attain the objects described herein below.